Exploring the exploding internet

Submarine cables

The internet depends heavily on underwater cables, which carry information across the world's oceans. This map shows 93 of the world's major submarine cable systems, as well as 28 planned systems that are due to enter service by 2011.

Submarine carrying capacity

In 1956, North America was connected to Europe by an undersea cable called TAT-1. It was the world's first submarine telephone system, although telegraph cables had crossed for the ocean for a century.

Trans-Atlantic cable capacity soared over the next 50 years, reaching nearly 10 Tbps in 2008.

In recent years, the annual growth of trans-Atlantic capacity has slowed, while the growth rates on the intra-Asian and Europe-Asia routes have increased rapidly.

Countries are colour-coded according to the amount of capacity deployed by carriers, ISPs, and enterprises to carry traffic across international borders (see "estimated international bandwidth usage by country", bottom left)